Shipping and storage drum with screw on locking cover

ABSTRACT

A shipping and storage drum with a screw on locking cover comprises an open end drum, a plastic cover and a locking member. The open head drum comprises a sidewall open at a top end by a threaded plastic chime. The chime comprises an annular wall having a rounded top edge with a plurality of thread segments and a flange extending outwardly from the annular wall below the thread segments and having a flange opening. Each thread segment comprises a plurality of threads extending outwardly from the annular wall. The thread segments are circumferentially spaced by non-threaded portions. A circumferential length of each non-threaded portion is similar to a circumferential length of each thread segment. The plastic cover has a central circular wall surrounded by a downwardly opening generally U-shaped wall for receiving the chime. The U-shaped wall comprises an outer annular sidewall and an inner annular sidewall connected by a rounded channel for sandwiching the chime. A flange extends outwardly from the outer annular sidewall and has a flange opening. The outer annular wall has a plurality of inwardly extending thread segments each having a plurality of threads. The thread segments are circumferentially spaced by non-threaded portions. A circumferential length of each non-threaded portion is similar to a circumferential length of each thread segment. The cover is selectively screwed onto the chime with a fractional turn of the cover with the chime rodded top edge being sealed in the rounded channel. The locking member is insertable through the flange openings to prevent the cover from backing off of the drum.

CROSS REFERENCE TO RELATED APPLICATIONS

There are no related applications.

FIELD OF THE INVENTION

This invention relates to a shipping and storage drum and, moreparticularly, to a drum with a screw on locking cover.

BACKGROUND OF THE INVENTION

In one form of a conventional shipping and storage container, anenlarged drum is used. The drum may be, for example, a 55 gallon drum.Such drums have found wide usage for shipping and storing liquid orgranular products. For example, such drums have been used for storingfood products and for storing hazardous products.

A typical drum includes a tubular sidewall closed at one end by a bottomwall and at another end by a top wall. Such containers may have afiberboard sidewall and metal top and bottom walls, may be made entirelyof metal, or may be made entirely of plastic, or be of compositeconstruction. Drums of fiberboard are generally not suitable forcarrying liquids. While metal drums are, they tend to be expensive andheavy and are not usable in the food industry unless made of stainlesssteel.

Such drums are classified as open head drums or tight head drums. With atight head drum, the top wall is generally permanently affixed to thesidewall. The top wall includes relatively small openings for access tothe interior of the drum. Conversely, an open head drum has a coverremovably received thereon. Typically, the container is filled byremoving the cover.

More recently, plastic drums have found wide acceptance. Customers oftendesire that the drum be a one-piece drum having an integral cover.However, such a drum is typically made by blow molding, which is a timeconsuming and expensive process. Also, the drums tend to be of lesserquality as there may not be uniform distribution of the plasticmaterial.

Even more recently, threaded drum plastic covers have been provided forselectively closing a unitary plastic open head drum to effectivelyprovide a tight head drum. Such a drum and cover are illustrated in U.S.Pat. No. 6,056,143. This patent includes a continuous thread on thedrum. Multiple turns of the cover must be made to effectively secure thecover on the drum, with a gasket providing a seal.

The present invention is directed to further improvements in shippingand storage drums.

SUMMARY OF THE INVENTION

In accordance with the invention, there is provided a screw on drumcover for selectively closing an open head drum with a fractional turnof the cover.

Broadly, there is disclosed herein a shipping and storage drumcomprising an open head drum and a plastic cover. The open head drumcomprises a sidewall open at a top end by a threaded plastic chime. Thechime comprises an annular wall having a rounded top edge with aplurality of thread segments extending outwardly from the annular wall.The thread segments are circumferentially spaced by non-threadedportions. A circumferential length of each non-threaded portion issimilar to a circumferential length of each thread segment. The plasticcover has a central circular wall surrounded by a downwardly openinggenerally U-shaped wall for receiving the chime. The U-shaped wallcomprises an outer annular sidewall and an inner annular sidewallconnected by a rounded channel for sandwiching the chime. The outerannular wall has a plurality of inwardly extending thread segments. Thethread segments are circumferentially spaced by non-threaded portions. Acircumferential length of each non-threaded portion is similar to acircumferential length of each thread segment. The cover is selectivelyscrewed onto the chime with a fractional turn of the cover and the chimerounded top edge is sealed in the rounded channel.

It is a feature of the invention that the drum chime and the cover eachinclude eight thread segments.

It is another feature of the invention that each drum chime and coverthread segment comprises three threads.

It is a further feature of the invention that each chime thread segmentcomprises a stop for limiting threaded movement of the cover onto thechime.

It is still another feature of the invention that the drum furthercomprises a flange extending outwardly from the annular wall below thethread segments and the cover comprises a flange extending outwardlyfrom the outer annular sidewall. Aligned openings are provided in eachof the flanges and a locking member is provided for insertion in theopenings to lock the cover on the drum.

It is still another feature of the invention that the inner annularsidewall comprises a plurality of outwardly extending ribs.

It is an additional feature of the invention that the chime rounded topedge seals against each of the outer annular sidewall and the innerannular sidewall.

It is still a further feature of the invention that the threads haveabout a ¼″ pitch.

It is yet another feature of the invention that the chime has a diameterof at least about 15″.

There is disclosed in accordance with another aspect of the invention ashipping and storage drum with a screw on locking cover comprising anopen end drum, a plastic cover and a locking member. The open head drumcomprises a sidewall open at a top end by a threaded plastic chime. Thechime comprises an annular wall having a rounded top edge with aplurality of thread segments and a flange extending outwardly from theannular wall below the thread segments and having a flange opening. Eachthread segment comprises a plurality of threads extending outwardly fromthe annular wall. The thread segments are circumferentially spaced bynon-threaded portions. A circumferential length of each non-threadedportion is similar to a circumferential length of each thread segment.The plastic cover has a central circular wall surrounded by a downwardlyopening generally U-shaped wall for receiving the chime. The U-shapedwall comprises an outer annular sidewall and an inner annular sidewallconnected by a rounded channel for sandwiching the chime. A flangeextends outwardly from the outer annular sidewall and has a flangeopening. The outer annular wall has a plurality of inwardly extendingthread segments each having a plurality of threads. The thread segmentsare circumferentially spaced by non-threaded portions. A circumferentiallength of each non-threaded portion is similar to a circumferentiallength of each thread segment. The cover is selectively screwed onto thechime with a fractional turn of the cover with the chime rodded top edgebeing sealed in the rounded channel. The locking member is insertablethrough the flange openings to prevent the cover from backing off of thedrum.

Further features and advantages of the invention will be readilyapparent from the specification and from the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a shipping and storage drum with screwon locking cover according to the invention;

FIG. 2 is an exploded view of the drum of FIG. 1;

FIG. 3 is a bottom perspective view of the cover according to theinvention;

FIG. 4 is a perspective view of a locking member;

FIG. 5 is a sectional view taken along the line 5-5 of FIG. 2;

FIG. 6 is a sectional view taken along the line 6-6 of FIG. 2;

FIG. 7 is a sectional view taken along the line 7-7 of FIG. 2;

FIG. 8 is a sectional view taken along the line 8-8 of FIG. 2;

FIG. 9 is a detailed partial perspective view of the drum;

FIG. 10 is a sectional view taken along the line 10-10 of FIG. 1;

FIG. 11 is a sectional view taken along the line 11-11 of FIG. 1; and

FIG. 12 is an enlarged sectional view taken along the line 12-12 of FIG.1.

DETAILED DESCRIPTION OF THE INVENTION

In the illustrated embodiment of the invention, as disclosed in thedrawings, a shipping and storage container 20 is shown to comprise aunitary plastic open head drum 22 and a unitary plastic threaded drumcover 24. With reference to FIGS. 1 and 2, the drum 22 has a rightcircularly cylindrical sidewall 26 connected to a bottom wall 28 todefine an interior space 30. The drum 26 is open at a top end 32.Particularly, and referring also to FIGS. 7 and 8, the top end 32comprises a threaded plastic chime 34. The chime 34 comprises an annularwall 36 having a rounded top edge 38 with a plurality of thread segments40 extending outwardly from the annular wall 36. The thread segments 40are circumferentially spaced by non-threaded portions 42. In theillustrated embodiment of the invention, the circumferential length ofeach non-threaded portion 42 is similar to a circumferential length ofeach thread segment 40.

The wall thickness of the chime annular sidewall 36 may be slightlygreater than the wall thickness of the sidewall 26. However, the drumincludes a seamless, continuous inner surface 44 between the chimeannular wall 36 and the sidewall 26. A flange 46 extends outwardly at ajunction between the annular wall 36 and the sidewall 26. A plurality ofsupport ribs 48 extend outwardly from the sidewall 26 and are connectedto the underside of the flange 46.

In the illustrated embodiment of the invention, the drum 22 is of onepiece molded plastic construction and may be formed of polypropylene orpolyethylene or the like. As will be apparent, the drum 22 could be acomposite structure using fiberboard or metal, or the like, with aplastic chime secured thereto in any known manner. The drum 22 isadapted for storage of bulk materials and would typically have adimension in the range of 15-½″ to 23-½″ diameter at the top end 32.

In the illustrated embodiment of the invention, there are eight threadsegments 40 separated by eight non-threaded portion 42. Each threadsegment would use up approximately 22.5° of circumference.Advantageously, the thread segments may use a slightly smaller amountsuch as about 21°. However, the lengths could be different, as could thenumber of thread segments 40. Each thread segment 40 comprises threethreads 40-1, 40-2 and 40-3, see FIG. 9. A stop 50 is provided at oneend of the lowermost thread 40-3. A plurality of circumferentiallyextending openings 52 are provided in the flange 46. An opening 52 isprovided associated with each thread segment 40 but locatedcircumferentially within the bounds of the non-threaded portions 42proximate the stops 50, as is particularly illustrated in FIG. 9.

Referring to FIGS. 1-3, the drum cover 24 is integrally formed ofone-piece injection molded plastic construction. The cover 24 may bemolded of polypropylene or polyethylene. The cover 24 is in the form ofa closure having a central circular wall 54 of a size slightly smallerthan the size of the chime 34. The circular wall 54 is surrounded bydownwardly opening generally U-shaped wall 56 for receiving the chime.The U-shaped wall 56 comprises an outer annular sidewall 58 and an innerannular sidewall 60 connected by a rounded channel 62, see FIGS. 5 and6, for sandwiching the chime 34. An annular ridge 64 extends upwardlyfrom the channel wall 62. Inner reinforcing ribs 66 integrally connectto the circular wall 54, the channel wall 62 and the ridge 64. A flange68 extends outwardly from the bottom of the outer annular sidewall 58.Outer reinforcing ribs 70 are integrally connected to the flange 68, theouter annular sidewall 58, the channel wall 62 and the ridge 64. Theouter reinforcing ribs 70 are co-located with the inner reinforcing ribs66.

Referring particularly to FIG. 3, a plurality of thread segments 72extend inwardly from the outer annular sidewall 58 and are separated bynon-threaded portions 74. In the illustrated embodiment of theinvention, there are eight thread segments 72 separated by eightnon-threaded portions 74. As with the drum 22, each thread segment 72would utilize approximately 22.5° of circumference for each segment andadvantageously may be slightly less, on the order of 21°. Thus, thecover includes a thread segment 72 for each drum thread segment 40.

Spacing between the cover outer annular sidewall 58 and inner annularsidewall 60 is greater than thickness of the drum chime 34. A pluralityof ribs 76 are provided in the U-shaped wall 56 extending outwardly fromthe inner annular sidewall 58, see FIG. 3. The ribs 76 providereinforcement for the chime 34, as described below.

Corresponding to the drum thread segments 40, each cover thread segment72 includes three threads 72-1, 72-2 and 72-3, see FIG. 12. Inaccordance with the invention, the cover 24 is screwed onto the drumchime 34 with a fractional turn of the cover 24 with the chime roundedtop edge 38 being sealed in the rounded channel wall 62, as isparticularly illustrated in FIG. 12. The threads of the thread segments40 and 72 may have a relief angle on the order of 10° and a pitch ofabout ¼″. This provides for approximately 15/1000 vertical movement ofthe cover 24 relative to the drum 22 to close with a turn of about ⅛revolution. With this turn, the chime top end 38 is sealed in therounded channel wall 62 at both an inside and an outside to provide aseal without use of a gasket, see FIG. 12. The internal ribs 76, whilespaced from the chime 36, provide support during use. Each stop 50limits rotational movement of the cover 24 and thus preventsover-tightening. Particularly, the stop 50 limits rotational movement ofthe lowermost cover threads 72-3, as will be apparent.

For preventing the cover 24 from backing off the drum 22, an opening 78is provided in the cover flange 68 having a size corresponding to thatof the drum flange openings 52. A circular opening 80 is providedthrough the upper wall 64. Referring to FIGS. 2 and 4, a locking member82 is illustrated. The locking member 82 comprises a bridge 84connecting opposite fingers 86 having narrowed portions 88. A strap 90extends upwardly from the bridge 84 and terminates in a bifurcatedelement 92. In use, the bifurcated element 90 is inserted through theopening 80 to loosely retain the locking member 82 to the cover 24 withthe strap 90 passing through the opening 80, as illustrated in FIG. 1.Thereafter, the locking member can be inserted through the cover flangeopening 78 into one of the aligned drum flange openings 52, as shown inFIG. 1, by flexing the fingers 86 toward one another. This prevents thecover 24 from backing off after being closed and sealed.

The use of a broken thread in the form of a plurality of thread segmentsallows for less than a full turn to close the cover 24 on the drum 22providing ease of use. A locking feature is retained by use of thelocking member 82. Moreover, the drum 20 is self sealing. The drum isillustrated with eight flange openings 52, one for each thread segment40. This enables the cover 24 to be threaded at any of eight angularpositions. As is apparent, the drum could include a single opening 52 orthe cover could include as many as eight angular openings 78, asnecessary or desired. The locking member 82 is not required forperformance, but is used to prevent the cover 24 from backing off thedrum 22, as described.

Thus, in accordance with the invention, there is provided a shipping andstorage drum wherein a cover is selectively screwed on with a fractionalturn and providing a self sealing feature.

1. A shipping and storage drum comprising: an open head drum comprisinga sidewall open at a top end by a threaded plastic chime, the chimecomprising an annular wall having a rounded top edge with a plurality ofthread segments extending outwardly from the annular wall, the threadsegments being circumferentially spaced by non-threaded portions, acircumferential length of each non-threaded portion being similar to acircumferential length of each thread segment; and a plastic coverhaving a central circular wall surrounded by a downwardly openinggenerally U-shaped wall for receiving the chime, the U-shaped wallcomprising an outer annular sidewall and in inner annular sidewallconnected by a rounded channel for sandwiching the chime, the outerannular wall having a plurality of inwardly extending thread segments,the thread segments being circumferentially spaced by non-threadedportions, a circumferential length of each non-threaded portion beingsimilar to a circumferential length of each thread segment, wherein thecover is selectively screwed on to the chime with a fractional turn ofthe cover and the chime rounded top edge being sealed in the roundedchannel.
 2. The shipping and storage drum of claim 1 wherein the drumchime and the cover each included eight thread segments.
 3. The shippingand storage drum of claim 1 wherein each drum chime and cover threadsegment comprises three threads.
 4. The shipping and storage drum ofclaim 1 wherein each chime thread segment comprises a stop for limitingthreaded movement of the cover onto the chime.
 5. The shipping andstorage drum of claim 1 wherein the drum further comprises a flangeextending outwardly from the annular wall below the thread segments andthe cover comprises a flange extending outwardly from the outer annularsidewall.
 6. The shipping and storage drum of claim 5 further comprisingaligned openings in each of the flanges and a locking member forinsertion in the openings to lock the cover on the drum.
 7. The shippingand storage drum of claim 1 wherein the inner annular sidewall comprisesa plurality of outwardly extending ribs.
 8. The shipping and storagedrum of claim 1 wherein the chime rounded top edge seals against each ofthe outer annular sidewall and the inner annular sidewall.
 9. Theshipping and storage drum of claim 1 wherein the threads have about a ¼″pitch.
 10. The shipping and storage drum of claim 1 wherein the chimehas a diameter of at least about 15 inches.
 11. A shipping and storagedrum with a screw on locking cover comprising: an open head drumcomprising a sidewall open at a top end by a threaded plastic chime, thechime comprising an annular wall having a rounded top edge with aplurality of thread segments and a flange extending outwardly from theannular wall below the thread segments and having a flange opening, eachthread segment comprising a plurality of threads extending outwardlyfrom the annular wall, the thread segments being circumferentiallyspaced by non-threaded portions, a circumferential length of eachnon-threaded portion being similar to a circumferential length of eachthread segment; a plastic cover having a central circular wallsurrounded by a downwardly opening generally U-shaped wall for receivingthe chime, the U-shaped wall comprising an outer annular sidewall and ininner annular sidewall connected by a rounded channel for sandwichingthe chime, and a flange extending outwardly from the outer annularsidewall and having a flange opening, the outer annular wall having aplurality of inwardly extending thread segments each having a pluralityof threads, the thread segments being circumferentially spaced bynon-threaded portions, a circumferential length of each non-threadedportion being similar to a circumferential length of each threadsegment; and a locking member, wherein the cover is selectively screwedon to the chime with a fractional turn of the cover and the chimerounded top edge being sealed in the rounded channel and the lockingmember is insertable through the flange openings to prevent the coverfrom backing off of the drum.
 12. The shipping and storage drum with ascrew on locking cover of claim 11 wherein the drum chime and the covereach included eight thread segments.
 13. The shipping and storage drumwith a screw on locking cover of claim 1 wherein each drum chime andcover thread segment comprises three threads.
 14. The shipping andstorage drum with a screw on locking cover of claim 11 wherein eachchime thread segment comprises a stop for limiting threaded movement ofthe cover onto the chime.
 15. The shipping and storage drum with a screwon locking cover of claim 11 wherein the drum flange comprises anopening associated with each thread segment for receiving the lockingmember.
 16. The shipping and storage drum with a screw on locking coverof claim 11 wherein the locking member is tethered to the cover.
 17. Theshipping and storage drum with a screw on locking cover of claim 11wherein the inner annular sidewall comprises a plurality of outwardlyextending ribs.
 18. The shipping and storage drum with a screw onlocking cover of claim 11 wherein the chime rounded top edge sealsagainst each of the outer annular sidewall and the inner annularsidewall.
 19. The shipping and storage drum with a screw on lockingcover of claim 11 wherein the threads have about a ¼″ pitch.
 20. Theshipping and storage drum with a screw on locking cover of claim 11wherein the chime has a diameter of at least about 15 inches.